This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Introduction. The USDA Draft Policy on Environmental Enhancement for Nonhuman Primates has been developed to provide more specific guidelines as to what measures sufficiently address the psychological needs of captive primates, but research is needed to guide its implementation. This project is providing direct benefit to the primate well-being and management of the Tulane National Primate Research Center colony. Rhesus macaques were studied due to their widespread use in biomedicine. Focus was placed on social grouping and human interaction as enrichment. Methods. Using behavioral, physiological, and clinical data, the following were compared 1) the effects of continuous full contact, continuous protected contact (social access via barred panels), and intermittent full contact for pair-housing rhesus macaques, and 2) the effects of several quantities and forms of human/primate interaction on the behavioral well-being of singly-housed individuals of both sexes. Subjects are drawn from the following populations: those mother-reared in a social setting, those mother-reared without other social partners, and nursery-reared individuals, some with and some without peer contact in infancy. Results/Discussion. Social grouping: both continous and intermittent full contact pair housing confer similar behavioral benefits (reduced abnormal and anxiety-related behavior, increased activity level), and do not result in differences in the incidence of wounding. Fewer behavioral benefits and no differences in wounding were observed in protected contact. Less affiliation occurs in protected contact, and subjects show higher levels of anxiety-related behavior. Human interaction: unstructured interaction or low levels of positive reinforcement training produced no behavioral changes, but intensive training for subjects with severe abnormal behavior reduced levels of these behaviors. This project aims to provide the scientific underpinning for decisions relating to the changing regulatory climate governing the behavioral management of non-human primates.